Shaft for roasting-furnaces.



E. J. FOWLER. SHAFT FOR ROASTING FURNACES. APPLIGATION FILED 141311.24, 191a.

Patented June 16, 1914:.

UNITED STAIIEd rs rnn'r curator;

EDWARD J. FOWLER, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO GENERAL CHEMICAL COMPANY, OF NEW SHAFT F61? ROASTING-FURN'ACES;

To QM whom it mag concern 1 Be it known that I, EDWARD J. Fenian a citizen of the United States, and a resident of the city of San Francisco, county of San l rancisco, and State of: California, have invented anew and useful Improvement in Shafts for Roasting--1 urnaces, of which the following, taken in coni'iection with the accoinpanving r wings specification.

My invention relates to roasting luinaces, especially'such as are used ior roastting ores, and such as are provided with stationary hearths upon which the ore is stirred and distributed by rakes or plows aiiixcd to rotating arzns said arms being in vturn ailixcd to and rotatable with a central vertical shaft which extends through central apertures in the hearths and is rotated by any suit-able mechanism. A furnace of such type is described and illustrated in the patent to John B. Francis Herreshotl, No.

976175, dated November 22, 1910.

More particularly my invention relates to the central rotatable shafts of such furnaces, of thetype in which the shaft is provided with an axial passage for conducting a cooling medium into of the ral ble arias, rounding said axial passage, for conducting the medium from passagesof the rabble arins to the exterior of the furnace and the lobject of my invention is to produce a shaft bf such kind. which will be easy of 1nauufactur'e and assembling or dismounting and will be free from other defects and disadvantages of shafts known before my inrention, as, for instance, Warping and luicltliiu;- due to the intense heat to which such shafts are subjected.

Referring to the accompanying drawings illustrative of an embodiment of my invention, Figure 1 is an axial section through a portion of a sectional shaft constructed in accordance With my invention. Fig. 2 is a plan view of one of the sections thereof, and Fig. 3 is a cross section along the line 3 3 of'Fi 1.

The shaft illustrated. is composed of a suitable number of superposed sections of which three only are sh own in the drawings. Each section is secured at its ends to the adjacent sections by means of suitable fasten ing means such as the bolts 1 cooperating with. the apertured abutting end flanges or lugs :2 of the sections. The sections are gen- Specification of Letters Patent.

cal wall 3 and with an annular passage sur- YORK, N. Y., A CORPORATION OF NEW YORK.

Patented an e rail-a e rally of similar structure so that a descripllOIl of one ofthein will be applicable to all.

1'" ita cl,

sect: is generally cylindrical in term.

Coimeutric' with the anitcr cylindrian inner cylindrical wall 4, these walls being held in. separated relation by suitable means such as the'radial ribs 5. The structure thus forms an axial passage 6 which is separated from and surrounded by an annular passage 7. At the pie as at which, rabble arms are to be fastened to the armsJthe outer wall is suitably conformed to coi iperate with fastening devices i'or said arms such' (a'm'forinations as 'SllOfl Il inc udinjlf an uihvardly projecting, flanged bo.

ss 8 which ltPl'OVldQtl with a passage 9 adapted to connect the annular space 7 with one of the -iassagcs oi the cooperating hollow rah ble arm and with a passage 10 which continued by means of a. suitable tubular construction 11 so as to connect the axial pas sage G with a passage of the rabble arm;

In the device shown the sections are articulatedtogether in axial alincirie'ut, the outer walls'l of adjacent sections abutting each other-at their ends whereliiy the annula r passa cs 7 of the sections are in comuniuication with each other. The bolts 1 cooperatin with the flanges 2 of the sections insure a close contact between the sections and prevent lealia go. The inner Walls of the sections aline with each other so that the axial passages 6 of the sections connnuuicate with each other without leakage and that at the same time the inner wall of each section will be capable of expansion and. contraction movements in a longitudinal direction independently of the inner Wall of the other sectiou. A s shown the inner Wall 4 slightly longer than the outer Wall 3, projecting beyond the end of the latter at one end of the section. This tubular projcczing end 12 telescopes w'ilhiin the end 13 of the adjoining; in-

ner wall so that the Walls are relatively inovable longitudinally.

in the operation of the furnace a cooling medium, preferably air at ordinary temperature, is induced or forced throngs the axial passage 6 and the various passages 10 into the rabble arms; attertravcrsiug passages in the arms it is discharged therefrom through. the passages 9 into the annular passage 7 from which it may escape into the atmosphere. In traversing the arms the air takes up hc'at therefrom, thus cooling; the

Elli

2 the plane of the outer same, and the thus heated air is ducted into the annular passage readily beunderstood that the inner channel 6 of the shaft contains air at ordinary temperature, and the annular passage 7 contains air at .a considerably higher temperature while the gases externally of the shaft have an extremely high temperature due to com- 7 bustion upon the hearths of the furnace. 13) The temperature in the passage 6 may be 60 to 100 F. in the passage 7, 200 to 400 F. and externally of the shaft 1100 to 1600 F. It will be seen therefore that the inner wall 4 is of amuch lower temperature than the 15 outer wall 3; consequently in actual use of the furnace they will expand unequally. The slidable joint 12 -13 will permit such unequal, expansion without injury of any kind to the shaft. The projection 12 beyond face of the flange 2 at one end of each section acts as a centering guide for the portion 13 of the inner Wall of the adjoining section, and, as will readily be understood, is of material aid in facilitating 5 the assembling of the sections to form a complete shaft.

I claim} 1. A shaft provided with an axial passage and an annular passage surrounding said. axial passage and separated therefrom by a cylindrical wall, said wall being composed of sections, said sections being connected by a then conslidalolejoint, substantially as and for the 7. It willi purpose describ 2. A hollow shaft comprising outer and inner cylindrical walls and means for holding said walls spaced apart in concentric relation, said inner wall being composed of sections, said sections being connected by a slidable joint, substantially as and for the purpose described.

3. A hollow shaft comprising articulated sections, each having outer and inner spaced walls, the outer walls of adjoining sections abutting each other and the inner walls thereof being connected by a slidablc joint, substantially as and for the purpose described.

4. A hollow shaft comprising articulated sections, each having concentrically arranged outer and inner cylindrical Walls spaced apart and means for connecting the outer walls of adjoining sections together with the ends thereof abutting each other, the inner Walls of said sections being con nected by a telescopic joint.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

7 EDWARD T. FOWLER.

Witnesses DUDLEY BAIRD, F. 131mm. 

